JJF 1832-2020 Calibration Specification of (1 mT~2.5 T) Magnetometers English
1 Scope
This Specification is applicable to the calibration of magnetometers for measuring DC magnetic fields in the range of 1 mT–2.5 T, and also to the calibration of the DC magnetic field measurement part of multi-functional magnetometers.
2 Normative references
The normative references of this Specification are as follows:
JJF 1013-1989 Terms in common use and their definitions for the magnetic metrology
For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
3 Terms and meteorological units
3.1
magnetometer
instrument for measuring magnetic field strength or magnetic flux density (magnetic induction)
3.2
zero drift
variation of the indicated value of a magnetometer deviated from the zero position when its probe is placed in a zero magnetic field chamber
3.3
basic range
range with the optimal maximum permissible error of magnetic flux density
4 General
A magnetometer is an instrument used to measure the magnetic flux density (magnetic induction) at a spatial point for an object, typically a Hall effect magnetometer. Magnetometers are divided into digital and pointer magnetometers according to the display mode, with their schematic block diagrams as shown in Figures 1 and 2, respectively. The probes of magnetometers are divided into radial probes and axial probes according to the measured magnetic field direction.
Figure 1 Schematic block diagram of a typical digital magnetometer
Figure 2 Schematic block diagram of a typical pointer magnetometer
The magnetic flux density shall be calculated by using Equation (1).
(1)
where,
B——the magnetic flux density of DC magnetic field, T;
EH——the Hall electromotive force generated in the semiconductor wafer, V;
d——the thickness of the semiconductor wafer, m;
RH——the Hall coefficient of the semiconductor wafer, m³/C;
I——the current passing through the semiconductor wafer, A.
Contents
Introduction i
1 Scope
2 Normative references
3 Terms and meteorological units
3.1 magnetometer
3.2 zero drift
3.3 basic range
4 General
5 Metering characteristics
5.1 Indication error of magnetic flux density
5.2 Indicated value difference of the probe in forward and reverse directions
5.3 Zero drift
5.4 Ascending and descending variation
6 Calibration conditions
6.1 Environmental conditions
6.2 Standard and other equipments for measurement
7 Calibration items and methods
7.1 Calibration items
7.2 Calibration methods
8 Expression of calibration results
9 Recalibration interval
Annex A Influence of the angle between the Hall plate and the magnetic field on measurement results
Annex B Example of uncertainty evaluation for the measurement of indication error of magnetic flux density
Annex C Format of original records for magnetometer calibration
Annex D Format of pages inside the calibration certificate
